General - Narrative (Details) - USD ($) $ in Thousands	Jan. 01, 2021	Jun. 30, 2021		Mar. 31, 2021	Dec. 31, 2020		Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings		$ (795,666)			$ (788,578)
Allowance for credit losses - Loans		199,775	[1]	$ 201,082	130,648	[1]	$ 121,119	$ 99,454	$ 80,284
Allowance for credit losses on unfunded loan commitments		20,500		$ 20,500	0
Allowance for credit losses		245			0
Loans		9,121,250			9,243,174
PPP loans
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Loans		415,800			667,100
State and municipal
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses		245			0
Cumulative effect of ASC 326 adoption
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings	$ 68,040
Percent of increase in allowance	57.00%
Allowance for credit losses - Loans	$ 74,055				74,055
Life of loan portfolio	4 years
Allowance for credit losses on unfunded loan commitments	$ 20,500	$ 20,500
Loans	4,776
Cumulative effect of ASC 326 adoption | State and municipal
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Allowance for credit losses	$ 245				$ 245

[1] Beginning January 1, 2021, the amount is based on the current expected credit loss methodology. Prior to January 1, 2021, the amount is based on the incurred loss methodology. See additional details in NOTE 1. GENERAL of these Notes to Consolidated Condensed Financial Statement.